static function Instance()
 {
     if (MainWPChildBackUpWordPress::$instance == null) {
         MainWPChildBackUpWordPress::$instance = new MainWPChildBackUpWordPress();
     }
     return MainWPChildBackUpWordPress::$instance;
 }
 function backup_wp()
 {
     if (!version_compare(phpversion(), '5.3', '>=')) {
         $error = sprintf(__('PHP Version %s is unsupported.', 'mainwp-child'), phpversion());
         MainWPHelper::write(array('error' => $error));
     }
     MainWPChildBackUpWordPress::Instance()->action();
 }